Need advice on deployment of campus-wide mail system

[Shahjehan Khatri <Shah@ASU.Edu>]

Hello!  For the next semester, we are planning to have our student 
population using Unix-Pine.  We are going to have a couple of "login 
servers" with Pine clients, and a couple of "IMAP servers."  The latter 
will be SPARCstation 1000 machines running Solaris 2.3.

One option we have considered is as follows:

Have the IMAP servers share a dual-ported RAID package.  Each IMAP server 
would have half of the RAID disks locally-mounted and half NFS-mounted.  
Then, each user would have an account on each IMAP server, but this would 
be transparent to him.  He could simply point to IMAP.ASU.EDU, which 
would resolved to IMAPa.ASU.EDU or IMAPb.ASU.EDU, depending on the load.  
Another advantage would be that, if one of the machines went down, we 
could transfer the disks to the other one.  

Has anyone out there implemented such a system?  Does anyone see a 
significant problem with this?

Another question is whether we should use ZMailer or sendmail V8.  We 
already have a modified mail.local which delivers to home directories.  
(This was a hand-me-down.)  Is it involved to get ZMailer to deliver to 
home directories and take quotas into account?

We don't need a very smart mailer, since it would simply send all outgoing 
mail to our "Post Office."  However, ZMailer supports posting to 
newsgroups, which we'll want in the future.

Would running 2 copies of sendmail against the same (NFS-shared) file space 
be a problem?  We could have a higher-priority MX record for one of the 
IMAP servers, but the mailer on the other one could potentially be 
started if the first mailer were busy?  Would ZMailer be a better choice 
in this regard, since it can be installed in "client-server" mode?

Back to the IMAP servers, another option would be to divide our users
between them.  Then we wouldn't have to worry about NFS idiosyncrasies,
but would be hard-pressed to balance the load and tell users which IMAP
server to point to. 

Yes another approach would be to start filling the first IMAP server, and 
once we're done with it, start using the next one.

Any comments will be greatly appreciated.

Sincerely,

  Shahjehan Khatri